Maps, in digital form and otherwise, may represent roads as simple lines that approximate road geometries at a course level. In general, widths of the lines can represent an actual width of the road and/or a type of the road. However, maps that use lines in various styles for representing roadways do not convey information about finer aspects such as a number of lanes, the presence of additional exit lanes, bicycle lanes, sidewalks, crosswalks, and so on. This lack of information is, in part, because the information is generally unavailable and is also difficult to acquire.
For example, in one approach, lanes and other more granular features of a road are not encoded within the map and must be manually annotated. In further approaches, various vehicles are outfitted with GPS and used as probes to determine lane configurations. For example, GPS locations of a vehicle are logged in order to determine lane-level paths within a road. However, using GPS information in this manner generally requires a vehicle to drive along each lane of a road including exit ramps, turn lanes, and so on. This type of approach to acquiring the map information for a single intersection or segment of the road may represent a multitude of logged passes through the segment/intersection in order to acquire a complete representation. Moreover, the information itself (e.g., GPS information) does not always provide an accurate representation since buildings, tunnels, and other forms of interference can impair the accuracy and/or overall ability to precisely determine locations of a vehicle.